Jesse OBrien Posted February 9, 2014 Share Posted February 9, 2014 (edited) I searched. The signal to noise ratio was really bad. I'm gearing up to install megasquirt 3 in my l28et, but I've had a hard time finding definitive documentation on what works and what doesn't. I've come across lots of anecdotal information, but I'm wondering if someone has put all the facts together into one place for ms3 and the l28et. Which sensors are typically used? Which distributor/coil options have given the best results? At this point, I'm just trying to get the car to run with as little hassle as possible, and installing MS seems like the fastest, most straightforward way to do that. My most important question is: What components MUST be replaced or worked around when installing ms3 in an l28et? Edited February 9, 2014 by Jesse OBrien Quote Link to comment Share on other sites More sharing options...
winstonusmc Posted February 9, 2014 Share Posted February 9, 2014 You could put MS3 on the L28ET without changing any sensors. The big "but" here is the sensors have room for improvement to make the engine run more power with better economy. Let's start with the sensors: MAF- Sure you could keep the stock one and get it to work with MS3. I prefer a MAF, I run a Z32 300zx MAF and I love the drivability. Or you can do MAP, just use the onboard unit on the 3.0 board until you know more about megasquirt to want a different one. Head temp sensor - I use it and it works great. I can post up what I use for calibration if you want. TPS - this is really something that needs to be replaced for a MAP based system. Accel enrichment won't work on the stock switch, but a unit out of a newer 240sx can be used. A MAF system doesn't necessarily need a cell enrichment. Know sensor - off the shelf, the MS can't read it. The knock module for MS uses a different type of unit, so the stock unit will be unused. Distributer - it is fine for the stock coil and igniter. You will just have to modify the 3.0 board with the appropriate pull-up resistor. If you want to go more wild, then an aftermarket trigger wheel will be needed for coil-on-plug or external coil packs. Its available through DIY Autotune. Injectors - The stock injectors are low impedance so a resister will have to be wired in. If you are staying with batch fire, which is all you can do with the unmodified distributor, the the 3.0 board can handle the injectors without a resistor. If you use an MS3X to run the injectors, a resistor pack will be needed. I use a Nissan version, available through various 6cyl Nissans. I have also used Honda units as well, and they have a pretty spiffy heatsink on them. Air Intake Temp - This is needed if you plan on a MAP based system. I mounted mine in the aux injector hole, just drilled and tapped. I used a Chrysler 420a sensor from a Neon or Eclipse. I can also post that calibration too. Idle control - I don't have any, but some use Bosch units with success. Quote Link to comment Share on other sites More sharing options...
Jesse OBrien Posted February 9, 2014 Author Share Posted February 9, 2014 You could put MS3 on the L28ET without changing any sensors. The big "but" here is the sensors have room for improvement to make the engine run more power with better economy. Let's start with the sensors:Thank you for taking the time. MAF- Sure you could keep the stock one and get it to work with MS3. I prefer a MAF, I run a Z32 300zx MAF and I love the drivability. Or you can do MAP, just use the onboard unit on the 3.0 board until you know more about megasquirt to want a different one. The plan is to use the onboard MAP and keep boost levels low. I'm not adding an intercooler or any kind of water/meth injection this season, just trying to make the most of the stock equipment. I just ordered the 3.57 board, as I intend to modify the board as little as humanly possible (read: no modifications) to get this engine running reliably. Head temp sensor - I use it and it works great. I can post up what I use for calibration if you want. That would be superb, or if it's already been posted I'd be perfectly happy with a link to that thread (whatever forum it may be on). TPS - this is really something that needs to be replaced for a MAP based system. Accel enrichment won't work on the stock switch, but a unit out of a newer 240sx can be used. A MAF system doesn't necessarily need a cell enrichment. The stock l28et 'tps' is kind of a joke, so this makes perfect sense. I've seen the ka24e tps installed, and it seems really straightforward to me. Looks like a robust configuration. Know sensor - off the shelf, the MS can't read it. The knock module for MS uses a different type of unit, so the stock unit will be unused. I'll have to do some research on this to figure out exactly what I need to order. Distributer - it is fine for the stock coil and igniter. You will just have to modify the 3.0 board with the appropriate pull-up resistor. If you want to go more wild, then an aftermarket trigger wheel will be needed for coil-on-plug or external coil packs. Its available through DIY Autotune. I remember reading about this in the MS1/MS2 installation guide on diyautotune's tutorials/articles section. Injectors - The stock injectors are low impedance so a resister will have to be wired in. If you are staying with batch fire, which is all you can do with the unmodified distributor, the the 3.0 board can handle the injectors without a resistor. If you use an MS3X to run the injectors, a resistor pack will be needed. I use a Nissan version, available through various 6cyl Nissans. I have also used Honda units as well, and they have a pretty spiffy heatsink on them. Right now, I'm just planning MS3 in batch with the stock distributor. I'd love to swap out to a better fuel delivery setup (with a real fuel rail, a reliable fuel pressure regulator, etc) ... but I'm going to put that off as long as possible. Air Intake Temp - This is needed if you plan on a MAP based system. I mounted mine in the aux injector hole, just drilled and tapped. I used a Chrysler 420a sensor from a Neon or Eclipse. I can also post that calibration too. I picked up what seems like a simple solution: the GM closed element IAT directly from diyautotune. Idle control - I don't have any, but some use Bosch units with success. I haven't done any reading on this yet, but I'm going to be at all different temperatures and altitudes so idle control is probably worth having. Quote Link to comment Share on other sites More sharing options...
Gollum Posted February 17, 2014 Share Posted February 17, 2014 We've talked about this Jesse, but I'll post here for consolidated information, and also to help others that might lend a hand in knowing where things are at. Idle Control: With who you are, and what you plan to use the car for, this is completely unnecessary. Even if you traveled up 4,000ft, a simple key off/on should get your idle relatively close to stable again. If your idle started low at low elevation (like say 600rpm) and that was already kind of on the brink of manageable, then the ECU wouldn't have much ability to correct for the elevation change. That said, an ECU isn't supposed to idle an engine like that. Timing should be held in reserve (read: it's wasting timing and advancing timing would increase RPM) and the ECU should be running at stoich or possible even more lean. This means that if the ECU "needs to " there's room to advance timing and add fuel if it needs to correct for a stumbling idle, or a stable at the throttle. This is one area that EFI systems are head of heels ahead of carb'ed setups. Idle Conclusion: The only real reason an idle control valve solenoid would be needed is if you have VASTLY varying idle requirements, almost always prompted by something like an AC pump. Them come in handy when you want to start an engine at 20 degrees bellow zero, but 30-60 seconds of running the engine with the throttle cracked will get the engine idling just fine. When I was driving my S30-l28et every day I was too lazy to do this, and would just brake for the first few stop signs with all three pedals in. I found this to be a valuable skill to learn anyways... Spark: Stick with the stock dizzy, and follow the DIYautotune write up on wiring the dizzy to MS3 (same as MS2) which basically just uses a 100% stock DIZZY and spark system. The fancy thing here is that the 3.0+ boards can drive a coil directly, requiring no ignitor. You can use an ignitor if you'd like, but it's not required. The OEM configuration uses an ignitor, which is mounted to the coil bracket. Spark Upgrade: DIYautotune makes a disc you can put into the stock dizzy that will allow you to run full sequential spark. This is really handy, but realize you'll be subject to all the OEM dizzy issues. The dizzy has been known to jump a tooth in EXTREME application, and of course the timing can vary from reality as you're not reading the crank directly, and there IS play in the system. Plus optical signal CAN have signal strength issues, though most people seem to be fine with them. The attrition cost of this though starts to go crazy if you let it. It can easily end up costing you $500 to go full sequential if you're not careful. Injector Wiring: As stated, if you're connected to the MS3 wiring (not MS3X) then MS3 can drive them directly, without resistors. This will be in batch of course, as there's two spark outputs for MS3. It's often recommended that even if you're running batch to go ahead and wire up both spark outputs to alternate injection, which reduces load on the system. I feel there's sufficient documentation on this, but if you need some links I'll dig around for you. Air metering: Map is fine, and I feel preferred in so many ways. Most people don't realize how pick a MAF sensor is, and how you really need to keep airflow laminar for them to work correctly and provide accurate readings across the full range of use. This usually requires straight tubing on either side. In most OEM application, you'll see them close to the air filter on the inlet, and they'll have some form of a honeycomb filter in front of them to force the air to be well distributed across the tube area. Then following the senor there's at least 6" if not 10" of straight inlet tube that doesn't do anything crazy. This keeps the air from tumbling and causing the air to have pressure wave effects upstream at the sensor. You'll also notice that in systems where there ARE turns not too far from the sensor, that the tube sizing is still rather large, to keep air velocity low which promotes laminar flow in these turns. Meter Conclusion: Map simplifies this process immensely. The downside is that you really do need TPS enrichment that works well. So you really do NEED to upgrade the TPS, but I think you've got this figured out. If you want to go crazy, you could go MAP + MAF down the road, which is the direction all the OEM's have gone. This gives the best of both worlds, and allows an ECU to predict conditions faster and more reliably. This also gives the ECU ability to check the sensors against each other and figure out if something is amiss (like a rouge IAT sensor). The ECU can also calibrate for altitude changes while the engine is running, if programmed for it. I'm not sure if this ability has been programmed into megasquirt to date. Head Temp Sensor: Keep what you got. As long as you have a quality thermometer you can calibrate MS to whatever sensor you have and it will be rock solid. I just use a candy thermometer to check coolant sensors on the stove. IAT: You've already ordered one, and it should be perfectly fine. Just make sure to calibrate it per megamanual. Then make sure to be half-smart about mounting it. Sometimes it's quite hard to mount it in such a way that it won't get heat soaked, but see what you can do. Ideally you'd thread a large hole in the intake manifold, and then thread in a plastic boss that can take the temps, and then thread the sensor into that. The plastic will at least create a thermal barrier between the intake and the sensor, and the only heat soak will be from the engine bay heat sources. All that said, I can't say how many installs I've seen with very poor IAT mounting, yet their engine was running fine, and doing just fine down the 1/4 track... You can tune for a wide variety of bad habits... Knock Sensor: I'd say that the MAJORITY of us on hybridZ with a L28ET run with the sensor unplugged... The OEM ECU starts pulling timing when there isn't actually knock, so why is it even there? I feel it was a piece of insurance. If someone advanced the timing at the distributor then the ECU would still be pulling timing if someone decided to run full throttle up a steep hill in 5th gear at 25mph... Other than that, it really isn't needed at all. In fact, I've yet to talk with a tuner that's tuned engines in the four digit HP range that swears by having a knock sensor. All the ones I've talked to admit that the knock sensor is more of just another piece of information to log that can help track problems, and that it's never something to use as a rule when tuning. In other words, you don't just say "well I've got no knock on the sensor, so lets add more timing".... That's just bad tuning habits. Knock sensors should be tuned per application, as every engine will emit a whole host of noises that the sensors will pick up, but each engine will have a unique knock frequency that needs to be found and then the sensor calibrated for. Without all that engineering going into, the sensor is nearly worthless. And to me, all that work is worthless when it's just for extra log data that I'll probably never need unless I'm pushing record setting numbers on the L28ET. Base Tune: I can dig up all sorts of tunes for you yo look at, and copy/paste maps if you'd like, but I'd advise against this. My opinion on this has changed a LOT in the last year as I've been reading more and more on tuning. This book has been the most clear and concise gathering of information that's actually been useful to me. http://www.amazon.com/Engine-Management-Advanced-Greg-Banish/dp/1932494421/ref=sr_1_1?s=books&ie=UTF8&qid=1392596002&sr=1-1&keywords=advanced+engine+management+tuning In that book, Greg goes over how to establish a base tune (which megasquirt can calculate anyways) and what to tune first and why. Most people start with a base tune and just adjust things until the engine performs well and has the AFR readouts on their wideband that they're looking for. This is NOT the ideal way to tune, as it will make future upgrades VERY difficult, and will also make it very hard to change sensors that might read 2-5% different down the road. If you establish your tune CORRECTLY, then changing sensors, or even injectors will only require mild modifications to your tune. With a MAP based setup, you'll always need some attention to your tune when you make modifications to the VE of the engine (porting, cams, intake/exhaust changes, etc), but doing it right the first time will make subsiquent changes much easier to fix the tune on. The other nice thing about doing it RIGHT the first time on a turbocharged engine is that when you turn up the boost, you should be pretty close on your guesses. If you've tuned incorrectly, then there's a good chance that then you reach IAT temps higher than you've seen before then you get an output that's unexpected. But if the ECU has been tuned correctly, and what's going on in software actually mirrors reality, then higher than normal IAT will result in predictable outputs, and most likely less broken parts. Quote Link to comment Share on other sites More sharing options...
Gollum Posted February 17, 2014 Share Posted February 17, 2014 (edited) Take from this site: http://www.diyautotune.com/tech_articles/megasquirt_idle_tuning.html Concerning Idle: No IAC valve at all? Yes, you can run without an IAC valve. Just use your idle speed set screw to adjust it open enough that the engine doesn't stall on cold starts. Sure, your idle speed with the engine warmed up will be higher than it could be, and you'll have no way to adjust for stuff like the A/C or electrical loads, but it'll work. Edited February 17, 2014 by Gollum Quote Link to comment Share on other sites More sharing options...
FricFrac Posted February 17, 2014 Share Posted February 17, 2014 Gollum excellent info - not really much to add to that. Good point on the MAF as well - had quite a few friends with problems with engine swaps because of a lack of laminar air flow in the MAFs. MAP works great in my applications and it tough to get a good setup going with the MAF when you're trying to cram stuff into your engine bay with intercooler piping, etc. Proper tuning is critical. I had my first MS3 running great. The guy who bought the car added and intercooler, turned the boost up 35bs and had it tuned and gained another 50rwhp. Got rid of some hesitation as well. I calibrate all my CHTS with a thermometer, hot water and a multi meter. They are all close but each one can be different to some degree (no pun intended) so I just take the numbers down and add them to the parameters. Matt and Jerry at diyautotune.com wrote a great book with a lot of info directly related to MShttp://www.amazon.com/Performance-Fuel-Injection-Systems-HP1557-ebook/dp/B003QMLC5Q/ref=sr_1_1?ie=UTF8&qid=1392653857&sr=8-1&keywords=Performance+Fuel+Injection+Systems Quote Link to comment Share on other sites More sharing options...
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